Diastereoselective synthesis of tetrahydrofurans from aryl 3-chloropropylsulfoxides and aldehydes

Carbanions of aryl 3-chloropropylsulfoxides have reacted with nonenolizable aldehydes to provide 2,3-disubstituted tetrahydrofurans. The diastereoselectivity is attributed to the cyclic transition state of the aldol addition and has increased when the aromatic ring of the sulfoxide contains electron-withdrawing subsituents, whereas that of the aldehyde has electron-donating groups.